325 results on '"mineralogical analysis"'
Search Results
2. Laboratory X‐ray powder micro‐diffraction in the research of painted artworks.
- Author
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Švarcová, Silvie, Bezdička, Petr, Hradilová, Janka, and Hradil, David
- Subjects
- *
MINIATURE painting , *PAINTING , *PIGMENT analysis , *MURAL art , *PAINT materials - Abstract
Painted artworks represent a significant group of cultural heritage artifacts, which are primarily admired because of their aesthetic quality. Nevertheless, the value of each particular painting depends also on what is known about it. Material investigation of paintings is one of the most reliable sources of information. Materials in painted artworks (i.e. panel, easel and miniature paintings, wall paintings, polychromed sculptures etc.) represent an extensive set of inorganic and organic phases, which are often present in complicated mixtures and exhibit characteristics reflecting their geological genesis (mineral pigments), manufacturing technology (artificial pigments), diverse biological nature (binders or dyes) or secondary changes (degradation or intentional later interventions). The analyses of paintings are often made challenging by the heterogeneous nature and minute size of micro‐samples or, in some cases, even by the impossibility of sampling due to the preciousness, fragility or small dimensions of the artwork. This review demonstrates the successful implementation of laboratory X‐ray powder micro‐diffraction for material investigation of paintings, illustrating its efficiency for mineralogical analysis of (i) earth‐based materials indicating the provenance of paintings, (ii) copper‐based pigments pointing to their origin, and (iii) products of both salt corrosion and saponification enabling one to reveal the deterioration and probable original appearance of artworks. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
3. Comprehensive characterization and environmental implications of industrial and hazardous incineration ashes: insights into chemistry, mineralogy, elements' fractionation and leaching potential.
- Author
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Kasina, Monika, Telk, Anna, and Wendorff-Belon, Małgorzata
- Subjects
- *
HAZARDOUS waste incineration , *WASTE treatment , *X-ray powder diffraction , *WASTE management , *SOLID waste , *INCINERATION - Abstract
Global economic growth and population expansion contribute to heightened solid waste production, creating environmental challenges. Sustainable waste management, notably incineration, is crucial for volume reduction, energy recovery, and resource utilization. The escalating reliance on waste incineration underlines the critical necessity for detailed waste characterization. Our study focuses on industrial and hazardous incineration residues (IHWA) and provides essential insights into their mineral and chemical composition employing various analytical techniques, including sieve analyses, laser diffraction, X-ray powder diffraction, FT-IR spectroscopy, SEM-EDS, and leaching behavior, thus contributing to filling a gap in the current knowledge. The majority of IHWA particles (41%) were smaller than 500 μm, with a significant portion (34%) in the 200–400 μm range, which increases their leaching potential. Toxic elements, including Cr, Cu, and Zn, were detected at elevated levels, with Zn concentrations exceeding EU soil limits by over 250 times, what underscore environmental risks and demand proper waste treatment. The complexity of mineral composition and bonds within the sample indicates the necessity for a thorough environmental assessment to understand the potential impacts on the ecosystem. Sequential extraction revealed that Zn (90.32%), Cd (64.22%), and Hg were predominantly found in the mobile fractions, indicating a high potential for leaching and environmental hazards. In contrast, elements like Cu, Cr, and Pb were primarily associated with immobile fractions. Mineral phases such as calcite and halite dissolved during the first extraction step, while other crystalline phases, including quartz and magnetite, remained stable throughout the process. The stability of other mineral phases in all results and the low leaching potential of elements in IHWA indicate that some mineral phases could suppress the leaching efficiency of elements. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
4. Patterns of ceramic production in Colonia Augusta Achaica Patrensis (Patras, Greece): a petrographic and mineralogical approach.
- Author
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Kougia, N., Reynolds, P., and Iliopoulos, I.
- Abstract
The Roman provinces did not exist as entities but as a part of a complex system involving their urban and rural landscape, communications and networks. This paper explores evidence for ceramic production within the territory of the Augustan colony of Patras, highlighting the city’s significance as a major production center due to its strategic position in regional and long-distance trading networks. Regarding the archaeological evidence, 60 sites with evidence for ceramic production were studied, providing new data on their architectural structures, workshops and kilns as well as spatial organization within Patras and its territory. The prime focus of the work, focused on the definition of local Roman wares. Hence, 150 samples were selected from the kilns and their surrounding area for typological and fabric analysis. This paper offers the first systematic archaeometric analysis of Roman ceramics from the city of Patras and serves as a major guide-line for defining what was actually produced locally (e.g. grey and red sigillatas, plain ware vessels, ceramic building materials and amphorae). Petrographic analysis enabled us to determine the local compositional patterns establishing that there are five fabrics encountered among the various workshops with few compositional differences, indicating that they derive possibly from the same locally available clay deposits. Imported (Italian) terra sigillatas could also be successfully distinguished. Mineralogical analysis through X-Ray Powder Diffraction (XRPD) allowed the study of the nature of the raw materials used and enabled the estimation of kiln firing temperatures, which ranged from 700 to 1100 °C, thereby offering vital insights into ceramic technology. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
5. Chemical, Mineralogical, and Petrographic Analysis of the Mud Mortar from Fort Ikoma Historical Building in Serengeti National Park, Tanzania.
- Author
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CHUO, R. A., NYANGI, P., and KIFANYI, G.
- Abstract
The restoration of historical buildings especially the Fort Ikoma in Serengeti National Park, Tanzania requires knowing the material properties used in their construction by characterizing the composition and properties of the mortar to inform the sustainable restoration strategies. Hence, the objective of this paper was to investigate the chemical, mineralogical, and petrographic analysis of the mud mortar from the Fort Ikoma historical building in Serengeti National Park, Tanzania using appropriate standard methods. The results indicated predominant compositions by weight of mud mortar through chemical analysis were silica (59.82%), alumina (20.42%), and Iron (III) oxide (11.07%), which contributed to the higher pozzolanic activity (91.31%) and cementitious properties (Cementitious Index of 46.76) of the historical mud mortar. Mineralogical analysis revealed that a high amount of quartz (38%), nacrite (17%), and other materials such as albite, chlorite, and nepheline put up the ability of mud mortar to resist environmental pressures. The findings contribute to awareness of historical building materials and provide the technical basis for restoring the Fort Ikoma historical building in Serengeti National Park, Tanzania, and similar historical buildings. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
6. Geotechnical identification of soil deposits and clay sensitivity evaluation: A case study from East Algeria.
- Author
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Charef, Nouar, Berrah, Yacine, and Boumezbeur, Abderrahman
- Subjects
- *
SOIL classification , *SOIL compaction , *SLOPE stability , *SOIL testing , *SOIL composition - Abstract
This article provides an overview of a comprehensive study conducted in the Tebessa region of Algeria to identify and characterize sensitive soils susceptible to swelling. This phenomenon poses significant challenges to construction activities and infrastructure development in the area. The study employed a multidisciplinary approach, combining geotechnical and mineralogical analyses to understand the behavior of sensitive soils in the region. Geotechnical investigations involved laboratory identification tests, including Atterberg limits, grain size analysis, methylene blue value, sedimentometry, as well as mechanical tests: oedometer swelling and compressibility tests. Additionally, over 110 boreholes in four sectors were drilled in order to collect soil samples for the analysis. Classification of the studied soils was performed based on grain size distribution, Atterberg limits, and geotechnical properties, utilizing classification systems like LPC and GTR. Results indicated that the sensitive soils in the Tebessa region predominantly belonged to highly plastic clayey categories, exhibiting medium to extremely high swelling potential. Mineralogical analysis through X-ray diffraction provided insights into the composition of the clay fraction, with a focus on identifying swelling clay minerals, such as smectites. The study identified a significant presence of smectites in the soil samples, which are known for their high swelling potential. Integrating geotechnical and mineralogical analyses allows engineers to correlate mineral compositions with soil behaviors such as compaction, consolidation, and shear strength. This correlation predicts how the soil will respond to engineering activities such as construction and slope stability. In the Tebessa region, this integration improves the understanding of clayey soil behavior, aiding informed decisions for sustainable development and resilient infrastructure. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
7. ВЛИЯНИЕ УЛЬТРАТОНКОГО ИЗМЕЛЬЧЕНИЯ НА ТЕХНОЛОГИЧЕСКИЕ ПОКАЗАТЕЛИ ОБОГАЩЕНИЯ ОТВАЛЬНЫХ ХВОСТОВ
- Author
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Мамбеталиева, А. Р., Макашева, Г. К., Тусупбекова, Т. Ш., Калиаскаров, С. К., and Сагатбек, С.
- Subjects
- *
COPPER , *MINERALOGY , *CHALCOPYRITE , *MINERAL industries , *FLOTATION - Abstract
The challenges that the mining industry has to face in order to achieve tailings disposal in accordance with the principles of a closed-loop economy include improving rather limited knowledge about mineralogy, impurity concentrations and tailings volume in tailings dumps. It is also necessary to develop technologies to make the process economically feasible. In order to improve the performance of the grinding operation and have a significant impact on the enrichment of valuable components, the effects of ultrathin grinding on the degree of disclosure of copper minerals of dump tailings were studied. Based on optical and mineralogical studies, it was found that the completely uncovered chalcopyrite grains make up no more than 35% of the total number of grains, their size is mainly (by 60% relative) within the class of 10-45 microns. Analysis of the sieve characteristics of the tailings after ultrathin grinding shows that the highest concentration of copper falls on the thinnest class -0.006+0 mm, that indicates a high disclosure of copper minerals due to ultrathin grinding. Flotation tests to determine the effect of the degree of ultrathin grinding showed that with an increase in the fineness of grinding in the size class - 0.045 + 0 mm to 86%, the extraction of copper increases from 66.49 to 73.52%; gold 71.07 to 77.78%; silver 70.29 to 76.71%. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
8. Sedimentological evolution of the Quibas site: High-resolution glacial/interglacial dynamics in a terrestrial pre-Jaramillo to post-Jaramillo sequence from southern Iberian Peninsula.
- Author
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Laborda-López, Casto, Martín-Perea, David M., Del Castillo, Elia, Alías Linares, M. Asunción, Iannicelli, Claudia, Pal, Shubham, Arroyo, Xabier, Agustí, Jordi, and Piñero, Pedro
- Subjects
- *
OXYGEN content of seawater , *GLACIATION , *OXYGEN isotopes , *SEDIMENTATION & deposition , *SEQUENCE stratigraphy - Abstract
The sedimentary infill of the Quibas karstic site (Early Pleistocene, southern Spain) represents the only continuous succession with remains of continental vertebrates in Europe from pre-Jaramillo to post-Jaramillo age. The Quibas site, with a significant paleontological record, is dated between 1.1 and 0.9 Ma and offers a unique opportunity to carry out a paleoclimatic reconstruction of the time period immediately after the arrival of the first humans to western Europe. For this reason, defining the dominant sedimentary processes in the different stratigraphic units and the associated paleoenvironment is essential. The Quibas site is made up of two karstic features with two stratigraphic sequences: Quibas-Cueva, containing six lithostratigraphic units, and Quibas-Sima, which contains seven lithostratigraphic units. The detailed description and analyses of the stratigraphic sections have allowed the characterization of various autochthonous and allochthonous facies of cave deposits. Paleoclimatic proxies, inferred from sedimentological analyses, reveal a record of several alternating humid and arid phases resulting from the Early Pleistocene glacial-interglacial cycles, allowing correlation to the marine oxygen isotope record. The lowermost units (pre-Jaramillo) were deposited during a long-lasting interglacial, correlated to MIS 33–31. It was followed by an increase in aridity in the intermediate units of Quibas-Sima and uppermost unit of Quibas-Cueva (Jaramillo), revealing the beginning of a glacial period at the start of the Jaramillo subchron (1 Ma), which can be correlated to MIS 30. The upper Jaramillo and post-Jaramillo units suggest these were deposited in alternating periods of aridity and humid conditions, although less humid than the pre-Jaramillo period, probably representing the MIS 29 interglacial, the MIS 28 glacial and the MIS 27 interglacial. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
9. Direct aqueous mineral carbonation of secondary materials for carbon dioxide storage
- Author
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F. Schinnerl, T. Sattler, G. Noori-Khadjavi, and M. Lehner
- Subjects
Direct aqueous carbonation ,Secondary materials ,Industrial wastes ,Mineralogical analysis ,Carbonation efficiency ,Technology - Abstract
Mineral carbonation of secondary materials offers an innovative way of storing carbon dioxide in materials that instead would mostly go to waste. This study investigates the carbonation efficiency (CE) of 11 different secondaries from refractory production, waste incineration, and the paper industry compared to untreated and thermally activated serpentinite. To determine the chemical and mineralogical composition of the materials, various analytical methods, like X-ray fluorescence, X-ray diffraction, scanning electron microscopy, Brunauer-Emmet-Teller and thermogravimetric analysis have been employed, both before and after the direct aqueous carbonation process. Each material was examined over reaction times of 6 & 10 hours at 180 °C and a starting pressure of 20 bar in a 0.6 L stainless steel batch reactor. The received results were then compared to the theoretical CO2 uptake, defined as the maximum carbon dioxide storage potential achievable if all Ca, Fe and Mg ions were converted to carbonates. The findings indicate carbonation efficiencies of 14–65 % for secondary materials, compared to 0.7–14 % observed in the serpentinite samples. The highest uptakes were achieved by the refractory materials, primarily due to their high metal oxide content. However, a negative impact was observed from graphite-based carbon binders in the refractories, with increased leaching of these binders leading to a decrease in carbonation efficiency. Materials with higher SiO2 content showed reduced performance, suggesting a passivation layer buildup during carbonation.
- Published
- 2024
- Full Text
- View/download PDF
10. Chemical, Mineralogical, and Petrographic Analysis of the Mud Mortar from Fort Ikoma Historical Building in Serengeti National Park, Tanzania
- Author
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R. A. Chuo, P. Nyangi, and G. Kifanyi
- Subjects
Fort Ikoma ,Historical Mud Mortar ,Mineralogical Analysis ,Petrographic Analysis ,Serengeti National Park ,Science - Abstract
The restoration of historical buildings especially the Fort Ikoma in Serengeti National Park, Tanzania requires knowing the material properties used in their construction by characterizing the composition and properties of the mortar to inform the sustainable restoration strategies. Hence, the objective of this paper was to investigate the chemical, mineralogical, and petrographic analysis of the mud mortar from the Fort Ikoma historical building in Serengeti National Park, Tanzania using appropriate standard methods. The results indicated predominant compositions by weight of mud mortar through chemical analysis were silica (59.82%), alumina (20.42%), and Iron (III) oxide (11.07%), which contributed to the higher pozzolanic activity (91.31%) and cementitious properties (Cementitious Index of 46.76) of the historical mud mortar. Mineralogical analysis revealed that a high amount of quartz (38%), nacrite (17%), and other materials such as albite, chlorite, and nepheline put up the ability of mud mortar to resist environmental pressures. The findings contribute to awareness of historical building materials and provide the technical basis for restoring the Fort Ikoma historical building in Serengeti National Park, Tanzania, and similar historical buildings.
- Published
- 2024
11. Investigation of performance reduction of PV system due to environmental dust: Indoor and real-time analysis
- Author
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Saumya Ranjan Lenka, Sonali Goel, Priya Ranjan Satpathy, Bibekananda Jena, and Renu Sharma
- Subjects
Performance reduction ,Mineralogical analysis ,Image characterization ,Real-time analysis ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
This paper analyzes the effect of different types of dust on the reduction of PV systems' performance. The PV system installed on the field gives maximum output. However, in a real-time scheme, the PV system fails to generate the desired power output due to various realistic and unavoidable factors like soiling. Different dust particles accumulating on photovoltaic (PV) modules result in shadowing and reduced irradiance, impacting power production. The study investigates eight dust samples (ash, dirt, cement, brick powder, putty, wood dust, sand, and salt) in indoor and outdoor environments. It evaluates the decrease in power at solar irradiance levels of 500, 700, and 1000 W/m². The soiling experiments conducted indoors show that the maximum% reduction in power is 39.21 % in the case of Ash, while a minimum of 8.32 % in the case of red soil. The outdoor experiments suggest that red soil, sand, and brick dust can create huge power losses in the PV system, followed by ash powder, wood dust, putty dust, salt, and cement powder. The advantages of this research lie in its thorough analysis of several forms of dust and their impact on photovoltaic (PV) systems under different circumstances. Furthermore, the study emphasizes the crucial need for implementing dust control measures to maximize system performance, thereby providing insightful information for system design and maintenance procedures. The novelty of this study is to investigate the performance impact of various kinds of dust on PV systems, offering significant insights for improving system efficiency in real-world circumstances. The research enhances the reliability and applicability of its results by thoroughly assessing outdoor and indoor conditions, bridging the gap between laboratory results and practical applications.
- Published
- 2024
- Full Text
- View/download PDF
12. Dataset formation for sem-based images of commercial minerals using ml algorithms: case study for zircon in the Egyptian mountains
- Author
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khalil, kirolos N. R., El-Fishawy, Nawal, Ali, Mohamed, and Mohamed, Mokhtar A. A.
- Published
- 2024
- Full Text
- View/download PDF
13. Novel utilization of waste concrete powder in alkali-activated binder
- Author
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Aidarus Yonis, Prabhat Vashistha, Yanchen Oinam, Martin Cyr, and Sukhoon Pyo
- Subjects
Waste concrete powder ,Alkali-activated binder ,Mineralogical analysis ,Hydration analysis ,LCA analysis ,Technology - Abstract
This experimental study investigates a novel approach to utilize waste concrete powder (WCP) in conjunction with metakaolin as a precursor in the production of alkali-activated binder for sustainable consumption of construction and demolition waste. A Chapelle test confirms the presence of reactive silica in thermo-mechanically activated WCP. Different alkali-activated mixtures with metakaolin replacement ranging from 0 % to 80 % were prepared. The mixture with 40 % activated WCP, with a sodium silicate to sodium hydroxide ratio of 2, achieved better compressive strength than the reference sample without WCP. Mineralogical analysis of the mixture pastes revealed that activated WCP-based mixtures developed geopolymer gel and C-S-H gel, contributing to better strength properties in the case of the mixture with 40 % activated WCP. Life cycle analysis demonstrated that incorporating 40 % thermo-mechanically activated WCP by replacing metakaolin reduces carbon dioxide emissions by 49.5 % and 2.2 % compared to Portland cement and metakaolin-based binder, respectively.
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- 2024
- Full Text
- View/download PDF
14. Analysis of the hydrosedimentary circulation in the mouth of dominated wave environment using grain size analysis, wave/current modeling and image processing case of the principal Rivers in Zemmouri bay
- Author
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Yaiche Temam, Imene, Bouhmadouche, Mohamed, Hemdane, Yacine, Kessali, Nacer, and Amiri, Hadjer
- Published
- 2024
- Full Text
- View/download PDF
15. Noble Metals and Carbon Substances in the Uranium and Rare Metal Deposits of Central Asia
- Author
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Potseluev, A. A., Bezaeva, Natalia S., Series Editor, Gomes Coe, Heloisa Helena, Series Editor, Nawaz, Muhammad Farrakh, Series Editor, and Marin, Yuri, editor
- Published
- 2023
- Full Text
- View/download PDF
16. Characterization of fly ash stabilized residual laterite
- Author
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Adekemi Ayodele, Akinropo Olajumoke, Sibel Pamucku, Adeyemi Fajobi, Akindehinde Akindahunsi, and Emmanuella Foghi
- Subjects
california bearing ratio ,mineralogical analysis ,residual tropical laterite ,southwest nigeria soil ,xrd analysis ,Mining engineering. Metallurgy ,TN1-997 - Abstract
The effective use of residual laterite soils is usually hindered because of their mineralogy and high fines content. This paper studied the potential improvement in the geotechnical and mineralogical properties of fly ash-treated residual laterite collected from Southwest Nigeria. Some physical and geotechnical properties, such as plasticity, compaction, unconfined compressive strength (UCS), and California Bearing ratio (CBR) of untreated and treated laterites were determined using ASTM standard methods. Stabilization was achieved by mixing the laterite with varying proportions (0%, 3%, 6%, 9%, 12%, and 15% by mass of dry laterite) of fly ash. Mineralogical analysis of untreated and treated laterite was done using the X-ray diffractometer (XRD). The results showed a slight initial increase at low proportions of fly ash (at 3%) in the plasticity properties and a subsequent decrease (of up to 65%) afterward. The UCS and CBR of the treated laterite increased over 100% (maximum UCS 110% and maximum CBR 183%) at 6% fly ash content. XRD analysis showed the formation of new minerals, predominantly portlandite, within the stabilized soils. This study confirmed that using fly ash for the stabilization of residual laterite soils is potentially viable for road construction.
- Published
- 2023
- Full Text
- View/download PDF
17. Determination of the Basic Geotechnical Parameters of Blast-Furnace Slag from the Kremnica Region.
- Author
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Bulko, Roman, Masarovičová, Soňa, and Gago, Filip
- Subjects
- *
SLAG , *MINERAL aggregates , *COHESION , *INTERNAL friction , *AGGREGATE industry , *INFORMATION resources management - Abstract
A decisive aspect of site evaluation for construction is the presence of anthropogenic materials occurring in the geological environment. The geotechnical properties of blast-furnace slag were investigated as a potential substitute for aggregates in the construction industry. The basic geotechnical parameters of the slag were determined, which are critical for evaluating its stability, environmental impact, and usability in geotechnical construction. The research focused on monitoring the physical and mechanical properties of the two samples, and also included mineralogical analysis. The obtained results demonstrated that the slag belongs to the category of poorly graded gravel, G2/GP, and gravel with an admixture of fine-grained soil, G3/G-F. In addition, other important parameters, such as the water disintegration of the slag aggregate, the minimum and maximum bulk densities, the California bearing ratio (CBR), the oedometric modulus (Eoed), and shear tests (the angle of internal friction φ and cohesion c), were determined. The results from this paper provide important information for the proper management of blast-furnace slag so to minimize its environmental impact and achieve sustainability in the mining industry. At the same time, it enables a better understanding of the use of slag as a substitute for aggregates in geotechnical tasks. Despite its local importance in relation to the investigated case, the presented study has significant educational and scientific value for the construction sector, where it is necessary to evaluate anthropogenic activities and materials. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
18. Plasticity role in strength behavior of cement-phosphogypsum stabilized soils
- Author
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Xia Bian, Lingling Zeng, Feng Ji, Ming Xie, and Zhenshun Hong
- Subjects
Strength ,Stabilization ,Plasticity index ,Microstructure ,Mineralogical analysis ,Engineering geology. Rock mechanics. Soil mechanics. Underground construction ,TA703-712 - Abstract
Dredged soil and phosphogypsum are frequently regarded as wasted materials, which require further treatment to control their environmental impact. Hence, phosphogypsum is proposed as a binder to stabilize dredged soil, aiming at efficiently reducing and reusing these waste materials. In this study, the engineering properties of cement-phosphogypsum stabilized dredged soils were investigated through a series of unconfined compression tests, and the effects of plasticity index of original soils on the strength improvement were identified. Then, the microstructure test and mineralogical test were performed to understand the mechanism of physical role of original soils in strength improvement. The results revealed that the unconfined compressive strength significantly decreased with the increase in plasticity index at the same binder content. The essential factor for strength improvement was found to be the formation of cementitious materials identified as calcium silicate hydrate (CSH), calcium aluminate hydrate (CAH), and ettringite (Aft). The normalized integrated intensity of cementitious materials (CSH + CAH + Aft) by pore volume decreased with the increase in plasticity index. Consequently, the density of cementitious materials filling the soil pores controlled the effectiveness of strength improvement. More cementitious materials per pore volume were observed for the original soils with lower values of plasticity index. That is, the higher strength of stabilized soils with lower values of plasticity index was attributed to a packed structure forming by integrated fabric through denser cementitious components. It can be anticipated from the above findings that the effectiveness of stabilization treatment will significantly reduce with the increase in plasticity of origin soil.
- Published
- 2022
- Full Text
- View/download PDF
19. The Geysernaya River Alluvium (Kamchatka): Composition and Features of Formation.
- Author
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Lebedeva, E. V., Zakharov, A. L., and Mikhalev, D. V.
- Subjects
- *
ALLUVIUM , *HEAVY minerals , *MINERAL aggregates , *MUDFLOWS , *SEDIMENTS , *ZEOLITES - Abstract
A comprehensive analysis of the composition of the alluvium of the river with active gas–hydrothermal occurrences has been carried out for the first time. Common features in the lower and middle reaches of the Geysernaya River include poor roundness of boulders and pebbles (grades 1–2), poor grading of alluvium fine-clastic components, abundant rock fragments, and mineral intergrowths even in the fine-sand fraction. All this information is indicative of weak sediment disintegration and a high proportion of slope material in sediments, including that redeposited by mudflows. High contents of smectite–zeolite and other newly formed (secondary) mineral aggregates (up to 70% of the light fraction of 0.1–0.25 mm in size) and altered rock fragments (up to 70–80% in the pebble fraction of alluvium) make it possible to suggest a great effect of gas–hydrothermal activity on the processing of river-eroded rocks, as well as the secondary weathering of the alluvium within the thermal fields. The riverbed deposition is fragmentary and predominant in the areas of (1) the active slope material inflow (temporary dams), (2) flattening of the longitudinal profile in dammed reservoirs, and (3) mudflow material removal. Two dammed reservoirs formed over the past 15 years, as well as fine-sand layers in the low-terrace sediments are indicative of the fact that the Geysernaya River valley is characterized by the periodic formation of such short-lived basins. The deposition conditions of the fine-sand alluvium are different in sections of a single-branch channel and within dammed reservoirs and affect the ratio of the principal minerals of the heavy fraction. Abundant well-rounded gravel and coarse sand and their weathered appearance make it possible to assume that, along with the processing of large volumes of incoming slope and mudflow material, the Geysernaya River continues to cut in and to erode ancient fluvial sediments probably of the pre-caldera stage. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
20. Counterfeit Glass Beads during the East African Caravan Trade: Mineralogical and Gemmological Analysis.
- Author
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Biginagwa, Thomas John
- Subjects
GLASS beads ,FORGERY ,NINETEENTH century ,BEADS ,SUPPLY & demand - Abstract
This article presents results from mineralogical and gemmological analyses of imperfectly made tubular beads excavated at Kilwa Kivinje, a 19th century coastal caravan terminus in southern Tanzania. These beads are unique in size, their material, and colour, in addition to lacking treated cut ends. Because of their distinctive flaw, these beads required thorough laboratory analyses to determine how they compare to other glass beads from the same archaeological context. Although 19th century European travellers' accounts insist on glass beads being the popular commodity during the East African caravan trade, mineralogical and gemmological analyses revealed some of these beads to have been crafted from low-grade non-glass material. This prevented their standardisation in cut lengths, the permanency of coated colours, and the cut-ends treatment. These results justify speculation that these were counterfeits designed to pass for the original glass beads, possibly due to limited supply amidst high demand and the rapidly changing customer tastes for the much sought-after glass beads in East Africa during the height of the caravan trade. This is the first archaeological study in the region to examine the quality of traded glass beads during the caravan trade for their authenticity in artistry and material. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
21. Characterization of fly ash stabilized residual laterite.
- Author
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Ayodele, Adekemi L., Olajumoke, Akinropo M., Pamukcu, Sibel, Fajobi, Adeyemi B., Akindahunsi, Akindehinde A., and Foghi, Emmanuella E.
- Subjects
- *
LATERITE mines & mining , *FLY ash analysis , *COMPRESSIVE strength , *GEOTECHNICAL engineering , *X-ray diffraction - Abstract
The effective use of residual laterite soils is usually hindered because of their mineralogy and high fines content. This paper studied the potential improvement in the geotechnical and mineralogical properties of fly ash-treated residual laterite collected from Southwest Nigeria. Some physical and geotechnical properties, such as plasticity, compaction, unconfined compressive strength (UCS), and California Bearing ratio (CBR) of untreated and treated laterites were determined using ASTM standard methods. Stabilization was achieved by mixing the laterite with varying proportions (0%, 3%, 6%, 9%, 12%, and 15% by mass of dry laterite) of fly ash. Mineralogical analysis of untreated and treated laterite was done using the X-ray diffractometer (XRD). The results showed a slight initial increase at low proportions of fly ash (at 3%) in the plasticity properties and a subsequent decrease (of up to 65%) afterward. The UCS and CBR of the treated laterite increased over 100% (maximum UCS 110% and maximum CBR 183%) at 6% fly ash content. XRD analysis showed the formation of new minerals, predominantly portlandite, within the stabilized soils. This study confirmed that using fly ash for the stabilization of residual laterite soils is potentially viable for road construction. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
22. Tracing sediment transport history using mineralogical fingerprinting in a river basin with dams utilizing sediment sluicing.
- Author
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Ito, Kenichi, Matsunaga, Motohide, Itakiyo, Tomoya, Oishi, Hiroyuki, Nukazawa, Kei, Irie, Mitsuteru, and Suzuki, Yoshihiro
- Abstract
Sediment causes a serious problem in relation to dam function. A cooperative sediment sluicing operation has been under way since 2017 to prevent sediment from accumulating in dams in the Mimi River, Miyazaki, Japan. To achieve a smooth and stable operation, it is very important to determine the sediment source and a sediment transport system to maintain the dam's function. In the current study, the source and transport of sediment from the Mimi River basin have been analyzed with X-ray diffraction (XRD) to reveal the peaks of mineral species. The sediment samples were collected in the Mimi River basin from the Tsukabaru Dam to the sea in an area including 4 dams and 5 tributaries. In addition, the minerals in samples collected in 2014, before the start of the sediment sluicing operation, and from 2018 to 2020, after the start of the operation, were analyzed. An evaluation of the similarity of the sediment at each sampling point based on the X-ray diffraction peaks of mineral species showed that sediment distributed upstream was transported downstream in the year when the sediment sluicing was done. This result indicates that the sediment sluicing operation at dams ensured the continuity of the sediment distribution in the Mimi River basin. In addition, an investigation done in 2020 showed that sediment particles very similar to those of the upstream tributaries were deposited downstream because of extensive flooding caused by a large typhoon. The management of sediment transport has the greatest importance in a river basin where a dam is to be constructed. It is possible to trace the history of the sediment distribution and movement resulting from the operation of sediment sluicing by using sediment mineral analysis. [ABSTRACT FROM AUTHOR]
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- 2023
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23. Ánforas prerromanas y romano-republicanas (siglos III-I a. C.) procedentes de contextos productivos del Bajo Guadalquivir: caracterización técnica y composicional
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Violeta Moreno-Megías, Francisco José García-Fernández, Juan Jesús Martín-del-Río, Mercedes Borreguero-Cid, and Pedro José Sánchez-Soto
- Subjects
Amphorae ,Archaeometry ,Multivariant analysis ,Mineralogical analysis ,Petrography ,Clay industries. Ceramics. Glass ,TP785-869 - Abstract
Resumen: El presente trabajo aporta una investigación arqueométrica sobre piezas cerámicas de los siglos III-I a. C. halladas en contextos alfareros de la ciudad de Sevilla (Palacio Arzobispal) y Carmona (zona del Arrabal), pertenecientes en su mayoría a ánforas de tradición púnica y turdetana, o bien ya romanizadas. Entre los principales objetivos se ha pretendido su caracterización tecnológica y composicional, la comparación de las características de cada tradición productiva y la confirmación de la posible procedencia local de estas producciones.En total, han sido 13 las muestras estudiadas con análisis petrográfico de láminas delgadas, análisis químico mediante fluorescencia de rayos X y análisis mineralógico por difracción de rayos X. Los resultados químicos muestran su carácter sílico-aluminoso y cálcico, con contenidos variables de óxido de hierro, así como otros elementos minoritarios y trazas. El tratamiento estadístico ha diferenciado 3 conglomerados y una muestra que se distingue del resto. El análisis mineralógico ha identificado 8 fases cristalinas, unas ya presentes en las materias primas y otras formadas por tratamiento térmico. Destacan la illita, identificada como fase deshidroxilada, anortita, diópsido y gehlenita. En cuanto al análisis petrográfico, se han identificado tres grupos petrográficos que se corresponden composicionalmente con el contexto de origen de las muestras, diferenciando entre las piezas procedentes de Sevilla, las formas romanizadas de Carmona y la cerámica común y formas de imitación de este mismo enclave.Se realiza una estimación de las temperaturas de cocción, entre unos 820 °C y 850 °C en atmósfera oxidante. Por último, se ha discutido la procedencia de las materias primas empleadas, proponiéndose materias primas illítico-calcáreas con un origen localizado en el valle del Guadalquivir. Los resultados permiten corroborar la procedencia local de estas piezas, probablemente relacionadas con los hornos donde aparecieron, y aportan nuevas perspectivas para el estudio de la tradición alfarera local y los cambios que se operan con la implantación productiva romana. Abstract: The present work consists of an archaeometric investigation concerning ceramic samples, mostly unpublished, of the III-I centuries b.C. They were found in connection with kilns of the city of Sevilla (Archbishop's Palace) and the countryside (Arrabal zone, Carmona). They are identified with evolved variations of Iron Age amphorae of Punic and Turdetanian tradition, or already Roman typologies. The main objectives of this research include their technological and compositional characterization as well as the comparison of the characteristics of each manufacture tradition.An assemblage of 13 samples has been studied through petrographic analysis of thin sections, chemical analysis (X-ray fluorescence) and mineralogical analysis (X-ray diffraction). The chemical results showed the silico-aluminous and calcitic character of the samples, with variable contents of iron oxide as well as other minor elements and traces. The statistical treatment of the data by multivariant analysis has differentiated 3 conglomerates and one sample as an outsider. The mineralogical analysis has identified 8 crystalline phases, several of them already present in the raw materials and others formed by thermal treatment. It is interesting to note the illite, identified as dehydroxylated phase, anorthite, diopside and gehlenite. The petrographical analysis has identified 3 different petro-groups, which are correlated by a compositional point of view with the original context of the samples. Thus, according to these results, it has been possible to distinguish the manufactures of Sevilla from the Roman shapes, the common ware and the imitation types of Carmona.It has been discussed the possible solid-state reactions which yielded the crystalline phases identified by X-ray diffraction, besides an estimation of firing temperatures between 820-850 °C in an oxidant atmosphere. Finally, the possible sources for the raw materials used in the fabrication of these amphorae have been proposed in the Guadalquivir River valley, considering their illitic-calcitic characteristics.
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- 2022
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24. Study the effect of different operation parameters on the reaction shaft performance of a copper flash smelting furnace: Mass and energy balance analysis.
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Afrouzeh, Mohsen, Ehteshamzadeh, Maryam, Jafari, Saeed, and Borhannejad, Mehdi
- Abstract
Mass and energy balance analysis is one of the classical methods of modeling applied in the flash furnace smelting process. This method is an efficient method for degrading the theoretical parameters of silica flux and air required for oxidation processes. In this study, the reaction shaft of the Sarcheshmeh flash smelting furnace has been modeled using the mass and energy balance method. A modeling code has been developed to calculate the oxygen content required for oxidation processes and the silica flux for slagging. Different parameters are effective in the working conditions of the flash smelting furnace. In this research, the effect of concentrate mineralogical analysis, oxygen enrichment, flue dust share, and the amount of natural gas was investigated. The modeling results show that by increasing chalcocite in the feed mixture, the average temperature in the reaction shaft will decrease. Increasing the oxygen enrichment increases the temperature and reduces the amount of off-gases that leave the furnace. The calculation can be repeated via modeling from different modes until improved furnace conditions are achieved and smelting operation is controlled. [ABSTRACT FROM AUTHOR]
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- 2023
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25. Extraction of Iron and Alumina from Red Mud with a Non-Harmful Magnetization Sintering Process.
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Chen, Rui, Shi, Lin, Huang, Haoyong, and Yuan, Jie
- Subjects
- *
MUD , *LEACHING , *HAZARDOUS wastes , *MAGNETIC separation , *MAGNETIZATION , *WASTE recycling , *ALUMINUM oxide , *MAGNESIUM oxide , *ALUMINUM smelting - Abstract
Red mud, which could cause numerous problems to the environment, is a hazardous waste generated from the alumina smelting industry. In general, the storage and harmless utilization of red mud are hard to implement due to its fine particle size and high alkalinity. This study put forward a novel process to separate iron (MgFe2O4) and alumina (Al2O3) in red mud by a magnetization sintering method. The magnesium oxide was added to transform the nonmagnetic Fe2O3 into magnetic MgFe2O4 to achieve physical separation of iron-bearing minerals, and the alumina-bearing minerals were converted into dissoluble NaAlO2 minerals in a one-step reaction. The atmospheric pressure leaching process was adopted in this study for alumina resource recovery. To achieve clean alumina production, the silicate in the leaching solution was removed by adding the slightly soluble CaSO4, and the entire process becomes clean and harmless. The feasibility of the process was verified by thermodynamic analysis, and a series of experiments were performed to detect the optimum MgO/(Fe2O3 + MgO) ratio and the calcining and leaching conditions. The morphological and mineralogical characteristics of modified red mud, leaching red mud, and magnetic separation product were studied by X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM) energy dispersive spectroscopy (EDS). It was observed that under the optimal conditions with MgO/(Fe2O3 + MgO) of 14.89% to recover iron and aluminum, the corresponding recovery rates were 67.54% and 73.01% respectively, and the iron grade was 30.46%. The EDS results showed that the obtained Mg/Fe ratio of the magnetic separation product was 0.4677–0.528, which is slightly different from that of the standard MgFe2O4 at 0.5. This new method can promote the development of comprehensive utilization of red mud and iron production. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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26. Morphological and Mineralogical Characteristics of Atmospheric Microparticles and Chemical Pollution of Street Dust in the Moscow Region.
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Kolesnikova, Varvara M., Salimgareeva, Olga A., Ladonin, Dmitry V., Vertyankina, Victoria Y., and Shelegina, Anna S.
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- *
POLLUTION , *DUST , *RADIOACTIVE fallout , *ENVIRONMENTAL sciences , *FOREST reserves , *MINERAL dusts , *AIR pollutants - Abstract
Comprehensive morphological and mineralogical studies of atmospheric microparticles sampled on the roof of the museum complex and near roads in the town of Istra, Moscow region, have been carried out. Morphological research at different hierarchical levels revealed the multicomponent composition of microparticles and made it possible to identify the most characteristic groups of microparticles of natural and anthropogenic origin. The composition of the studied atmospheric microparticles is dominated by mineral grains of quartz and feldspars; biotite and calcite are singly noted, which reflects the ecological and geographical conditions of their formation, namely the Central Russian mineralogical province. A small share of technogenic particles in the composition of aerosol fallout indicates a low level of technogenic load and a favorable environmental situation in the study area, largely due to the protective functions of the forest park zone. The results of determining the material composition and calculating the enrichment factors also indicate a low level of technogenic impact on the natural environment. [ABSTRACT FROM AUTHOR]
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- 2023
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27. Mixed-dust pneumoconiosis in a dental technician: a multidisciplinary diagnosis case report
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Luigi Di Lorenzo, Francesco Inchingolo, Antonella Pipoli, Filippo Cassano, Maria Elena Maggiore, Angelo Michele Inchingolo, Sabino Ceci, Assunta Patano, Giuseppina Malcangi, Antonio Mancini, Giosi Longo, Rossella Attimonelli, Eugenio Maiorano, Rocco Laviano, Nicola Mariano Manghisi, Antonio Scarano, Felice Lorusso, Antonio Di Lorenzo, Alessio Danilo Inchingolo, and Gianna Dipalma
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Pneumoconiosis ,Dental technician ,Environmental analysis ,Mineralogical analysis ,Histologic analysis ,Diseases of the respiratory system ,RC705-779 - Abstract
Abstract Background In dental laboratories, exposure to crystalline silica can occur during procedures that generate suspended mineral dusts, e.g. dispersion of mixing powders, removal of castings from molds grinding, polishing of castings and porcelain, and use of silica sand for blasting. There is also a large list of toxic agents (acrylic resins, polymeric materials, etc.) used to produce removable and fixed prostheses, but also impression materials and more. Using personal protective equipment and other aids reduces the exposure to these potentially harmful agents. Case presentation We report the case of a 42-year-old male dental technician who began to suffer from a dry cough and exertional dyspnea after approximately 15 years of work. The operations he conducted for his job resulted in the generation of crystalline silica, aluminum, chromium and titanium dust. The worker did not regularly wear personal protective equipment and some of the above operations were not carried out in closed circuit systems. The Chest X-ray showed diffused micronodules in the pulmonary interstitium of the upper-middle lobes, bilaterally, and a modest left basal pleural effusion. Simple spirometry showed small airway obstruction in its initial stage. High Resolution Computerized Tomography of the chest showed bilateral micronodulation of a miliariform type, with greater profusion to the upper lobes, also present in the visceral pleura, bilaterally. Histological examination showed aggregates of pigment-laden macrophages forming perivascular macules or arranged in a radial pattern around a core of sclerohyalinosis. Scanning Electron Microscopy and Energy Dispersive Spectrometry revealed several mineral particles, typically characterized by the presence of crystalline silica and metal aggregates. The environmental concentrations of total dust and its respirable fraction were all lower than the relative TLV-TWA—ACGIH, yet not negligible. Conclusions The above findings and a multidisciplinary assessment led to the diagnosis of mixed dust pneumoconiosis s/q with 2/2 profusion of occupational origin. This diagnosis in a dental technician was supported for the first time in literature by environmental exposure analysis.
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- 2022
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28. Gypsiferous Gazha Soils of the Subboreal Zone of Eurasia.
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Yamnova, I. A. and Chernousenko, G. I.
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- *
GYPSUM in soils , *GYPSUM , *SODIUM sulfate , *DESERTS , *SOIL horizons , *MAGNESIUM sulfate - Abstract
Gypsiferous soils (gazha soils—soils formed from loose powdery gypsum sediments) under bioclimatic conditions of forest-steppe, steppe, semidesert, and desert of the subboreal zone are analyzed. Their morphological, micromorphological, mineralogical, and chemical properties are described. Gazha horizons of these soils may have different geneses: sedimentation, in situ weathering of hard gypsum rocks, and hydrogenic precipitation from groundwater. Despite the different origins of the gazha horizon, its morphology and properties have much in common: the gypsum content >50%, its powdery character with crystal size of <0.25 mm, and the presence of calcium carbonates and soluble salts with a predominance of sodium and magnesium sulfates. However, in some cases, the identification of the gazha horizon in the field and the chemical determination of gypsum give incorrect information about its presence; mineralogical analysis is necessary to determine the composition of the salts. An analysis of the micromorphological structure clearly demonstrates the genesis of gypsum: under hydrogenic conditions, when gypsum precipitates from groundwater or from lake and river water, gypsum material predominates and displays a subparallel microstructure, while in the in situ gazha or gazha originated from the lateral (colluvial) processes, gypsum crystals are deposited together with silicate plasmic material. [ABSTRACT FROM AUTHOR]
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- 2023
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29. Petrological and Mineralogical Characteristics of Exposed Materials on the Floors of the Lavoisier and Surrounding Craters.
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Yi, Eung Seok, Kim, Kyeong Ja, Wöhler, Christian, Berezhnoy, Alexey A., Kim, Yong Ha, and Moon, Seulgi
- Subjects
- *
FLOORING , *LUNAR craters , *NATIVE element minerals , *SPECTRAL reflectance , *IMPACT craters , *MINERALOGY - Abstract
Five floor-fractured craters (FFCs), Lavoisier crater and four craters surrounding it (Lavoisier C, Lavoisier E, Lavoisier F, and Lavoisier H), are distributed along the boundary between the northwestern part of the Oceanus Procellarum and the highlands. This study examines the uplifted or exposed materials on the fractured floors of these five impact craters using petrological, mineralogical, and morphological analyses. We inferred the processes that uplifted or exposed the materials from the subsurface to the crater floor using the Chandrayaan-1 Moon Mineralogy Mapper (M3) level 1b (thermally and topographically corrected spectral radiance) data and level 2 (spectral reflectance) data. The elemental abundances, petrological, and mineralogical characteristics of the study regions were mapped. We confirm that mare basalts and dark mantle deposits exist on the floors of these five craters. These two materials (mare basalts and dark mantle deposits) were used to identify minerals exposed on the floor surface of craters using spectral reflectance spectra. Two mineral groups were identified: pigeonite (or orthopyroxene in norite (low-Ca pyroxene) occurred in the craters Lavoisier, Lavoisier F, and Lavoisier H, and subcalcic augite (high-Ca pyroxene) occurs in the craters Lavoisier C and E. Our approach demonstrates that the characterization of uplifted or exposed surface minerals using elemental maps, spectral parameter composite maps, and reflectance spectra can provide information critical for prospective studies involving lunar geology and in situ resource utilization. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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30. NATURE OF PHOSPHATE DISTRIBUTION WITHIN THE GOLDEN WEATHERING CRUSTS OF THE TOMSK REGION
- Author
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Olga M. Yanchenko, Timofey V. Timkin, Valery G. Voroshilov, Tamara Yu. Yakich, and Mansour Ziaii
- Subjects
phosphates ,weathering crust ,mineralogical analysis ,scanning electron microscopy ,kolyvan-tomsk folded zone ,tomsk region ,Engineering geology. Rock mechanics. Soil mechanics. Underground construction ,TA703-712 - Abstract
The relevance of the research. In the Tomsk region, the weathering crusts are very widespread, their gold content has been established, but a detailed study of the mineral composition has not previously been carried out. The relevance of the research is caused by the need to identify the conditions for formation of weathering crusts and to establish the patterns of accumulation of a wide range of minerals in them. The main aim of the research is to study the morphological and chemical features, paragenetic associations and distribution of minerals of the phosphate group, division into primary, transformed, and newly formed, the use of phosphates as minerals-indicators of the conditions for the formation of weathering crusts and their relationship with the distribution of gold. The object: residual and redeposited weathering crusts of the Tomsk region and the minerals of the phosphate group contained in them. Methods. The crystal morphological features of minerals of the phosphate group, their paragenetic associations were studied microscopically using an OLYMPUS SZX10 stereomicroscope, the chemical composition of minerals was determined using a HORIBA Scientific XGT-7200 X-ray fluorescence microscope and a TESCAN VEGA 3 SBU X-50 X-50 EDS Max OXFORD scanning electron microscope. Results. In the weathering crusts of the Tomsk region, phosphates of the apatite group, rare earth elements, and aluminophosphates of the crandallite group have been found. Phosphate minerals are divided into groups: primary terrigenous phosphates, stable in weathering crusts and released during the destruction of bedrock (monazite, xenotime, apatite), hypergene-transformed, altered during weathering (monazite), and secondary (monazite, cularite, flitorensite, crandallite, goyacite, gorseixite, plumbogumite). Established in different zones of the weathering crust, phosphate associations for the most part represent links in the successive transformation of minerals from calcium and rare-earth phosphates to aluminum, indicating an increase in the acidity of the mineral formation environment. In the upper part of the hydrolysis zone of the residual weathering crust, the greatest accumulation of gold is noted.
- Published
- 2021
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31. Case study on the mineralogical and petrophysical analysis of reinforced concrete slabs of a highway viaduct of the S.G.C. Orte-Ravenna
- Author
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Elena Marrocchino, Chiara Telloli, Alessandra Aprile, Domenico Capuani, Davide Malaguti, and Carmela Vaccaro
- Subjects
Concrete ,Aggregates ,Damage ,Mechanical tests ,Mineralogical analysis ,Science ,Technology - Abstract
Abstract For the maintenance of the safety and security of people traveling on the road, renovation of the reinforced concrete is necessary, especially for bridge or viaduct slabs. Being able to quantify the degradation of slabs and propose methodologies for its retrofit or maintenance is crucial not only in the mineralogical-engineering field but also for socio-economic implications. In this study, samples of deck slabs of a viaduct from the highway E45 near the locality of Bagno di Romagna (Emilia Romagna, north of Italy) were subjected to a testing program to evaluate mechanical and mineralogical parameters through thermographic analyses, compression, and Ultrasonic Pulse Velocity tests and morphological observation. The analyses allow to better recognize the damage of the reinforced concrete samples and they have shown that the cause of the detachment of the asphalt has mainly a natural origin, due to temperature variations and precipitation, with a secondary cause in the anthropogenic impact. The work aims to understand the relationships between the structure of the aggregates and the characteristics of concrete to understand the development of degradation. This knowledge could be used to prevent future damages to the highways. Article Highlights Concrete slabs analysed provided information about the relation between damage level, mechanical behaviour, size and distribution of aggregates. Thermographic analyses were useful to understand how deep the damage was in the slabs and to detect any detachment of the asphalt. Compressive tests, through the failure load value, shown that the ultimate strength level decreased due to formation of microcracks.
- Published
- 2021
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32. Direct aqueous mineral carbonation of secondary materials for carbon dioxide storage.
- Author
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Schinnerl, F., Sattler, T., Noori-Khadjavi, G., and Lehner, M.
- Subjects
CARBON-based materials ,INCINERATION ,CARBON dioxide ,INDUSTRIAL wastes ,X-ray fluorescence - Abstract
Mineral carbonation of secondary materials offers an innovative way of storing carbon dioxide in materials that instead would mostly go to waste. This study investigates the carbonation efficiency (CE) of 11 different secondaries from refractory production, waste incineration, and the paper industry compared to untreated and thermally activated serpentinite. To determine the chemical and mineralogical composition of the materials, various analytical methods, like X-ray fluorescence, X-ray diffraction, scanning electron microscopy, Brunauer-Emmet-Teller and thermogravimetric analysis have been employed, both before and after the direct aqueous carbonation process. Each material was examined over reaction times of 6 & 10 hours at 180 °C and a starting pressure of 20 bar in a 0.6 L stainless steel batch reactor. The received results were then compared to the theoretical CO 2 uptake, defined as the maximum carbon dioxide storage potential achievable if all Ca, Fe and Mg ions were converted to carbonates. The findings indicate carbonation efficiencies of 14–65 % for secondary materials, compared to 0.7–14 % observed in the serpentinite samples. The highest uptakes were achieved by the refractory materials, primarily due to their high metal oxide content. However, a negative impact was observed from graphite-based carbon binders in the refractories, with increased leaching of these binders leading to a decrease in carbonation efficiency. Materials with higher SiO 2 content showed reduced performance, suggesting a passivation layer buildup during carbonation. • The study assesses secondary raw materials, like refractory residues, for CO₂ sequestration using mineralogical analysis • Compares carbonation efficiency of 11 Mg- and Ca-rich industrial wastes with serpentinite as a benchmark. • Uses XRF, XRD, SEM, TGA, and BET analyses to study chemical composition and structural traits tied to carbonation. • Provides new insights on refractory materials' potential for carbonation and CO₂ sequestration. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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33. Mineralogical insights into anion and cation dissolution behavior in calcium arsenic residue from copper smelting: Implications for safe disposal.
- Author
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Zhao, Xiaolong, Ma, Mengyu, Du, Ying, Ma, Wenbo, Wang, Guangli, and Du, Dongyun
- Subjects
LEAD ,COPPER smelting ,COPPER ,LIME (Minerals) ,MASS transfer ,HEAVY metals ,GYPSUM - Abstract
This study investigates the dissolution behavior of calcium-arsenic residue (CAR) sourced from a copper smelter in China, crucial for its safe disposal. Using mineralogical analysis, we identified fine powders, medium particles, and varying crystallinity in lumps, with calcium arsenate oxides comprising 56.03 % of the total weight. Arsenic dissolution is predominantly influenced by arsenic-containing mineral phases, with calcium arsenate oxides serving as the primary controlling phase. Other cations, including copper, zinc, calcium, and lead, behave according to their respective mineral phases. At a leaching pH of 3, concentrations of heavy metal ions such as As, Zn, Cu, and Pb exceed permissible limits set by the United States Environmental Protection Agency (USEPA), reaching approximately 3500, 155, 30, and 7.5 mg/L, respectively. The release of fluoride and chloride anions remains consistent throughout the system, largely unaffected by pH variations, at approximately 10 and 200 mg/L, respectively. Additionally, the competitive interaction between SO 4
2- and AsO 43- for Ca2+ ions promote SO 42- dissolution, leading to morphological changes in gypsum (CaSO 4 ·2 H 2 O). Under acidic conditions (pH=3), there's an increase in gypsum volume, with SO 42- leaching concentration around 1100 mg/L, while under alkaline conditions (pH=12), the SO 42- leaching concentration increases to around 4400 mg/L due to the dominance of AsO 43- . Kinetic analysis suggests that arsenic release involves a combination of diffusion and interfacial mass transfer. Overall, this study provides valuable insights into the characterization and dissolution behavior of CAR-related minerals, offering comprehensive data support for their safe disposal and landfilling. [Display omitted] • CAR is formed by intersecting and mixing multiple arsenic-bearing minerals. • Lower pH promotes cation leaching and SO 42- leaching is inhibited. • Competitive precipitation of SO 42- and AsO 43- occurred during the leaching of CAR. • Mixed diffusion and interfacial mass transfer to control As leaching. [ABSTRACT FROM AUTHOR]- Published
- 2024
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34. Methods of Magnetic and Mineralogical Analysis
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Ibragimov, Shamil, Kuzina, Dilyara, Mishenin, Sergey, Zakirov, Timur, Ibragimov, Shamil, Kuzina, Dilyara, Mishenin, Sergey, and Zakirov, Timur
- Published
- 2020
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35. CHARACTERIZATION AND PROCESSING OF LOW-GRADE IRON ORE FROM THE KHANGUET MINE BY ELECTROSTATIC SEPARATION.
- Author
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Tiour, F., Idres, A., Ould Hamou, M., and Boutarfa, F.
- Subjects
ELECTROSTATIC separation ,IRON ores ,X-ray fluorescence ,IRON mining ,ORE-dressing ,MINES & mineral resources - Abstract
Purpose. Choice of a method for treating the iron ore of the Khanguet mine depending on its characterization. Methodology. This work is focused on the study on physicochemical and mineralogical characterization of the poor iron ore of Khanguet mine, using multiple analysis techniques (X-ray diffraction, X-ray fluorescence, scanning electron microscope and optical microscope), to identify the chemical composition and mineral phases of the ore. The study also focused on the possibility of enrichment, using the electrostatic separation process. For this purpose, two main parameters are studied, such as, the voltage between the electrodes and the rotation speed of the roll. Findings. The results of the characterization show the possibility of using the process of electrostatic separation for the enrichment of the Khanguet ore, which allows increasing the content of Fe2O3 up to 58.46%. Originality. The originality of this work is the possibility to use the electrostatic treatment process for the poor iron ore of the Khanguet iron mine. Practical value. This study shows that the results obtained by the process of electrostatic treatment of ore are very significant; this technique makes it possible to obtain a concentrate with an iron content of 58.46% and to bring an added value to the company and the steelmaking industry, on the one hand, and, on the other hand, to eliminate reserves of these poor iron ores stored near the mining site, which is harmful for the environment. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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36. Sedimentological evolution of the Quibas site: High-resolution glacial/interglacial dynamics in a terrestrial pre-Jaramillo to post-Jaramillo sequence from southern Iberian Peninsula
- Author
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Laborda López, Casto, Martín Perea, David Manuel, Del Castillo, Elia, Alías Linares, M. Asunción, Iannicelli, Claudia, Pal, Shubham, Arroyo, Xabier, Agustí, Jordi, Piñero, Pedro, Laborda López, Casto, Martín Perea, David Manuel, Del Castillo, Elia, Alías Linares, M. Asunción, Iannicelli, Claudia, Pal, Shubham, Arroyo, Xabier, Agustí, Jordi, and Piñero, Pedro
- Abstract
The sedimentary infill of the Quibas karstic site (Early Pleistocene, southern Spain) represents the only continuous succession with remains of continental vertebrates in Europe from pre-Jaramillo to post-Jaramillo age. The Quibas site, with a significant paleontological record, is dated between 1.1 and 0.9 Ma and offers a unique opportunity to carry out a paleoclimatic reconstruction of the time period immediately after the arrival of the first humans to western Europe. For this reason, defining the dominant sedimentary processes in the different stratigraphic units and the associated paleoenvironment is essential. The Quibas site is made up of two karstic features with two stratigraphic sequences: Quibas-Cueva, containing six lithostratigraphic units, and Quibas-Sima, which contains seven lithostratigraphic units. The detailed description and analyses of the stratigraphic sections have allowed the characterization of various autochthonous and allochthonous facies of cave deposits. Paleoclimatic proxies, inferred from sedimentological analyses, reveal a record of several alternating humid and arid phases resulting from the Early Pleistocene glacial-interglacial cycles, allowing correlation to the marine oxygen isotope record. The lowermost units (pre-Jaramillo) were deposited during a long-lasting interglacial, correlated to MIS 33–31. It was followed by an increase in aridity in the intermediate units of Quibas-Sima and uppermost unit of Quibas-Cueva (Jaramillo), revealing the beginning of a glacial period at the start of the Jaramillo subchron (1 Ma), which can be correlated to MIS 30. The upper Jaramillo and post-Jaramillo units suggest these were deposited in alternating periods of aridity and humid conditions, although less humid than the pre-Jaramillo period, probably representing the MIS 29 interglacial, the MIS 28 glacial and the MIS 27 interglacial., Ministerio de Ciencia e Innovación, Generalitat de Catalunya, University Rovira i Virgili, European Union, MCIN/AEI/10.13039/501100011033, Depto. de Geodinámica, Estratigrafía y Paleontología, Fac. de Ciencias Geológicas, TRUE, pub
- Published
- 2024
37. Evaluation of different factors on metal leaching from nickel tailings using generalized additive model (GAM)
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Zhixiang Ye, Song Hong, Chao He, Yun Zhang, Yan Wang, Hua Zhu, and Haobo Hou
- Subjects
GAM ,Yunnan Province ,Mineralogical analysis ,Metal leaching ,Environmental pollution ,TD172-193.5 ,Environmental sciences ,GE1-350 - Abstract
Compared with sulfide tailings, the oxidation and transformation of certain substances in oxidized tailings into more soluble forms may affect the bioaccumulation and biomagnification properties and enhance the risk of toxic effects in the ecosystem. This study aimed to apply the generalized additive model (GAM) to evaluate factors affecting heavy metal leaching from nickel (Ni) tailings. We created an orthogonal experiment table (L18(37)) to evenly distribute the different combinations of factor values. The Ni tailings were immersed in solutions with different combinations of factor values for 16 d, and samples were taken on days 1, 2, 4, 7, 11, and 16 to measure the pH and heavy metal concentration of the leachate. The GAM was used to fit the concentration of heavy metals of the leachate and the initial factors of the leaching solution. The results showed that the pH and Cr concentration of the leachate increased with time and stabilized after 1 d (pH of approximately 7), while the Mn, Ni, and Tl concentrations gradually decreased and stabilized after peaking on the first day. An analysis of the GAM results showed that the Cr concentration was highly sensitive to the solid-liquid ratio (F = 127.8) and tailing particle size (F = 10.7). The Cr concentration of the leachate was significantly higher when exposed to a high solid-liquid ratio or a fine particle size, whereas the Mn, Ni, and Tl concentrations were highly sensitive to the KCl concentration and solid-liquid ratio (F = 77.4, 146.9, and 315.9 respectively). The GAM identified interactions between key factors, which have complex and strong effects on the leaching of tailings and the migration of heavy metals, either promotional or antagonistic. The prediction of the minimum Cr leaching concentration shows that GAM can be used to determine the conditions associated with minimum leaching concentrations of heavy metals and to effectively predict the metal concentrations of leachate. As such, the results of this study can be applied to the management of nickel tailings.
- Published
- 2022
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38. Mixed-dust pneumoconiosis in a dental technician: a multidisciplinary diagnosis case report.
- Author
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Di Lorenzo, Luigi, Inchingolo, Francesco, Pipoli, Antonella, Cassano, Filippo, Maggiore, Maria Elena, Inchingolo, Angelo Michele, Ceci, Sabino, Patano, Assunta, Malcangi, Giuseppina, Mancini, Antonio, Longo, Giosi, Attimonelli, Rossella, Maiorano, Eugenio, Laviano, Rocco, Manghisi, Nicola Mariano, Scarano, Antonio, Lorusso, Felice, Di Lorenzo, Antonio, Inchingolo, Alessio Danilo, and Dipalma, Gianna
- Abstract
Background: In dental laboratories, exposure to crystalline silica can occur during procedures that generate suspended mineral dusts, e.g. dispersion of mixing powders, removal of castings from molds grinding, polishing of castings and porcelain, and use of silica sand for blasting. There is also a large list of toxic agents (acrylic resins, polymeric materials, etc.) used to produce removable and fixed prostheses, but also impression materials and more. Using personal protective equipment and other aids reduces the exposure to these potentially harmful agents.Case Presentation: We report the case of a 42-year-old male dental technician who began to suffer from a dry cough and exertional dyspnea after approximately 15 years of work. The operations he conducted for his job resulted in the generation of crystalline silica, aluminum, chromium and titanium dust. The worker did not regularly wear personal protective equipment and some of the above operations were not carried out in closed circuit systems. The Chest X-ray showed diffused micronodules in the pulmonary interstitium of the upper-middle lobes, bilaterally, and a modest left basal pleural effusion. Simple spirometry showed small airway obstruction in its initial stage. High Resolution Computerized Tomography of the chest showed bilateral micronodulation of a miliariform type, with greater profusion to the upper lobes, also present in the visceral pleura, bilaterally. Histological examination showed aggregates of pigment-laden macrophages forming perivascular macules or arranged in a radial pattern around a core of sclerohyalinosis. Scanning Electron Microscopy and Energy Dispersive Spectrometry revealed several mineral particles, typically characterized by the presence of crystalline silica and metal aggregates. The environmental concentrations of total dust and its respirable fraction were all lower than the relative TLV-TWA-ACGIH, yet not negligible.Conclusions: The above findings and a multidisciplinary assessment led to the diagnosis of mixed dust pneumoconiosis s/q with 2/2 profusion of occupational origin. This diagnosis in a dental technician was supported for the first time in literature by environmental exposure analysis. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
39. Geotechnical Behavior and Physico-Chemical Changes of Lime-Treated and Cement-Treated Silty Soil.
- Author
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Bouras, Fawzi, Al-Mukhtar, Muzahim, Tapsoba, Nouffou, Belayachi, Naima, Sabio, Serge, Beck, Kévin, and Martin, Mylène
- Subjects
CALCIUM hydroxide ,SOIL cement ,SOILS ,CALCIUM aluminate ,POZZOLANIC reaction ,LIME (Minerals) - Abstract
An investigation performed on the interactions of silty soil treated with cement or lime demonstrates the strong relationship between microstructural phenomena and their engineering behavior. Cement hydration induces a rapid improvement in soil properties while the progressive pozzolanic reaction of lime leads to long-term improvement. Moreover, the cement-treated soil presents better mechanical properties (California bearing ratio and unconfined compressive strength). X-ray diffraction tests and thermo-gravimetric analyses show calcium aluminate hydrates in lime-treated soil and ettringite in cement-treated soil. Mineralogical changes and new hydrates formed in the treated soil demonstrate their positive effect on the engineering behavior of the soil. Swelling and indirect tensile strength indicate the soil suitability for treatment with specific amounts of binders. Cement-treated soil resists the immersion test, as ettringite and new calcium aluminate hydrate are detected by XRD after immersion, whereas dissolution of the unreacted lime and part of the calcium hydrates during the immersion test imply a low resistance to immersion of lime-treated soil. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
40. Quality Assurance Support (QA/QC System) of Mineralogical Analysis
- Author
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Yakushina, O., Gorbatova, E., Ozhogina, E., Rogozhin, A., Bezaeva, Natalia S., Series Editor, and Glagolev, Sergey, editor
- Published
- 2019
- Full Text
- View/download PDF
41. Using computational fluid dynamic simulation with Flow-3D to reveal the origin of the mushroom stone in the Xiqiao Mountain of Guangdong, China.
- Author
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Li, Jian-cheng, Wang, Wei, Zheng, Yan-ming, Wen, Xiao-hao, Feng, Jing, Sheng, Li, Wang, Chen, and Qiu, Ming-kun
- Subjects
CHEMICAL weathering ,DYNAMIC simulation ,WEATHERING ,MUSHROOMS ,STREAMFLOW ,STONE ,COMPUTATIONAL fluid dynamics - Abstract
Mushroom shaped rocks are not uncommon in nature, but their origin is often misunderstood because they can be formed by different natural forces. A huge mushroom stone in a stream valley of the Xiqiao Mountain of Guangdong, China is widely believed to be formed through the way of stream water erosion. However, the result of the simulation performed with Flow-3D in this study indicates that the mushroom shape of the rock could not have been sculpted by the flowing water erosion because the simulation result contradicts that of the field investigations: (1) the sediment brought by upstream flowing water tends to be deposited on the leeward side of the flowing water preventing the rock on this side form being eroded, but the narrowest part of the rock bottom is exactly located on this side of the rock and (2) the stream flow should erode the bed sediment and produce high abrasion on the rock surface on the upstream and lateral sides of the rock, respectively, but no abrasion marks are found on the same sides of the rock. Subsequent geological analyses in this study provide evidence that the narrow bottom of the mushroom stone was resulted from chemical and physical weathering happening within the sediment that used to deposit on the lee side of the stone. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
42. Assessment of Avroman Limestone Formation for Portland Cement Industry, Halabja Area, Kurdistan Region, NE-Iraq.
- Author
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Fatah, Chro M. and Mirza, Tola A.
- Subjects
LIMESTONE ,CEMENT ,MINES & mineral resources ,KAOLINITE ,ANALYTICAL geochemistry - Abstract
Copyright of Iraqi National Journal of Earth Sciences is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2021
43. Technological change and cultural resistance among southeast Iberian potters: analytical characterisation of Early Iron Age pottery from Castellar de Librilla.
- Author
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Cutillas-Victoria, Benjamín, Garrigós, Jaume Buxeda i, and Day, Peter M.
- Abstract
The beginning of relationships between autochthonous communities and Phoenicians from the earliest contacts in the eighth century BC made possible the exchange of ideas, technologies and people. This work analyses the development of the Early Iron Age potteries of the Iberian Southeast, the impact of the Phoenician presence and the agency that these local groups exercised on their ceramic assemblages until the fifth century BC. The incorporation of new archaeometric data from Castellar de Librilla, one of the region’s main autochthonous settlements, has been essential to improve our approach to these cultural encounters. A total of 63 representative individuals have been analysed through X‐ray fluorescence (XRF), X‐ray diffraction (XRD), thin-section petrography and scanning electron microscopy (SEM). The results point to the local production of ceramics previously considered as Western Phoenician pottery, and to the degree of specialisation of the potters established in the autochthonous settlements, combining traditional and new techniques from early in the period of contact. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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- View/download PDF
44. Marmora of the Traianeum of Italica (Santiponce, Seville, Spain): New data provided by archaeometric analysis.
- Author
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Becerra‐Fernández, Daniel, Ontiveros‐Ortega, Esther, and Beltrán‐Fortes, José
- Subjects
- *
WALL coverings , *MARBLE - Abstract
This article aims to identify a series of stone materials used in the ornamentation of the Traianeum of Italica (Santiponce, prov. Seville, Spain), the imperial cult shrine commissioned by Hadrian in honour of his adoptive father, Trajan, from a petrographic, mineralogical, and geochemical point of view. The study highlights the simultaneous use of local and, above all, foreign marbles. Local marbles from Almadén de la Plata (prov. Seville) and Hill of Mijas (prov. Malaga) were used particularly for wall coverings and pavements, whereas Luni‐Carrara marble stands out as the preferred ornamental foreign marble used in column shafts, bases, capitals, balustrade finishes, and so forth. In addition, cipollino marble was mainly used for the column shafts of the hecatostylon portico, but the analysis has not been able to specify its exact provenance, whether it is from Euboea or local, possibly the area of Almadén de la Plata. However, given that this was a construction promoted by the emperor, it might be possible that it would have come from Greece. Highlights: Analysis of marmora from Traianeum, Italica (Seville, Spain), has allowed to establish the source area of stone ornaments used in its monumentalization.The study methodology proposed in this paper is based on the characterization of archaeological pieces and quarries material.The types of marmora identified using archaeometric techniques are as follows: Luni‐Carrara, Almadén de la Plata (Seville), Chain of Mijas (Malaga), and a banded variety that can be called Cipollino, of Hispanic origin, most likely attributable to Almadén de la Plata (Seville). [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
45. SPECTROSCOPIC INVESTIGATION OF SOIL TREATED WITH AND WITHOUT ORGANIC MANURES.
- Author
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Haridha, R. Suya Padhra, Jeyamangalam, F., and Jenila, R. Mary
- Subjects
- *
MANURES , *FOURIER transform infrared spectroscopy , *KAOLINITE - Abstract
FTIR analytical study has been carried out to investigate the mineralogical composition of the soil. A field experiment was carried out at Servaikaranmadam of Thoothukudi district, Tamil Nadu during Kharif season in 2018 on sandy clay loam soil to access the effect of organic manures in the soil and to determine the chemical compositions of soil samples. The experiment was laid out in Randomized Block Design (RBD) with three replications. The experiment comprised of thirteen treatment combinations. The results of the present study revealed that soils have various mineral compositions namely Quartz, Kaolinite, Montmorillonite, Feldspar and Illite etc. The application of organic manures like Goat manure (G), Vermicompost (V) and Swine manure (S) in triple manure concentration at 17 t ha-1 reveals the presence of Organic Carbon along with the minerals, before and after harvest. This ensures a better yield of black gram (Vigna Mungo L.). [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
46. Biostimulation of sulfate reduction for in-situ metal(loid) precipitation at an industrial site in Flanders, Belgium.
- Author
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Pérez-de-Mora, Alfredo, de Wilde, Herwig, Paulus, Dirk, Roosa, Stephanie, Onderwater, Rob, Paint, Yoann, Avignone Rossa, Claudio, and Farkas, Daniel
- Published
- 2024
- Full Text
- View/download PDF
47. Novel utilization of waste concrete powder in alkali-activated binder.
- Author
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Yonis, Aidarus, Vashistha, Prabhat, Oinam, Yanchen, Cyr, Martin, and Pyo, Sukhoon
- Subjects
KAOLIN ,CONCRETE waste ,WASTE recycling ,POLYMER colloids ,CONSTRUCTION & demolition debris ,CARBON emissions ,SUSTAINABLE construction - Abstract
This experimental study investigates a novel approach to utilize waste concrete powder (WCP) in conjunction with metakaolin as a precursor in the production of alkali-activated binder for sustainable consumption of construction and demolition waste. A Chapelle test confirms the presence of reactive silica in thermo-mechanically activated WCP. Different alkali-activated mixtures with metakaolin replacement ranging from 0 % to 80 % were prepared. The mixture with 40 % activated WCP, with a sodium silicate to sodium hydroxide ratio of 2, achieved better compressive strength than the reference sample without WCP. Mineralogical analysis of the mixture pastes revealed that activated WCP-based mixtures developed geopolymer gel and C-S-H gel, contributing to better strength properties in the case of the mixture with 40 % activated WCP. Life cycle analysis demonstrated that incorporating 40 % thermo-mechanically activated WCP by replacing metakaolin reduces carbon dioxide emissions by 49.5 % and 2.2 % compared to Portland cement and metakaolin-based binder, respectively. • Thermo-mechanical treated WCP promises an alternative binder in the alkali-activated based concrete. • Burned-Milled WCP (BMWCP) demonstrated high performance in reactivity compared to Milled WCP and as-received WCP. • In terms of mechanical performance, incorporating 50 % BMWCP improved compressive strength compared to the reference samples. • BMWCP based binder significantly decreases the environmental impact and the CO 2 emissions in general. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
48. PROCESSING OF SLUDGE TAILS OF ENRICHMENT OF CHROME ORE.
- Author
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Serzhanova, Nuriya, Temirova, Saniya, Kuldeyev, Yerzhan, and Bondarenko, Igor
- Subjects
- *
CHROMITE , *METAL tailings , *MINING methodology , *FLOW charts , *FERROCHROME , *PROCESS mining , *ORES - Abstract
The physical and chemical characteristics of sludge from the chrome production in the Donskoy Ore Mining and Processing Plant (DOMPP) owned by TNK Kazchrome JSC have been studied. Researches have been performed to determine the gravity concentration ability of sludge tailings using fractional analysis, concentration tables. It was found that it is required to classify the initial sludge into size classes to obtain high technological parameters, and beneficiation with screw separators is ineffective. New data have been obtained for the chromite sludge beneficiation process using modern technological equipment that enables to separate into narrow material size fractions with their subsequent gravity concentration with the help of concentration tables. A concentrate with a content of 50.82% Cr2O3 and a middling product with a content of 30.85% Cr2O3 was obtained as a result of beneficiation of sludge tailings with a content of 28.89% Cr2O3 using concentration tables. The novelty of the work is in the improvement of the beneficiation flow chart for sludge tailings of DOMPP that includes the operation intended to classify sludge tailings into narrow size classes at the process beginning and their separate beneficiation with the help of concentration tables. A schematic diagram of DOMPP sludge tailings beneficiation with the production of a finely dispersed concentrate that is the starting material for the chrome pellet production used for ferrochrome smelting is recommended. The proposed flow chart for sludge tailings beneficiation will enable to involve the enterprise’s current and stale tailings in processing that will increase the technical, economic, and environmental parameters of production. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
49. Tuff-sandstones of Perekatnaya Formation: composition, genesis, sources of demolition (Ust’-Belsky Mountains, Koryak Highland)
- Author
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M. Yu. Gushchina, A. V. Moiseev, and M. I. Tuchkova
- Subjects
koryak highland ,perekatnaya formation ,lithology ,genetic diagrams ,granulometric analysis ,mineralogical analysis ,Engineering geology. Rock mechanics. Soil mechanics. Underground construction ,TA703-712 - Abstract
Research subject. In this work, we set out to investigate the petrographic, mineralogical and granulometric composition of tuff-sandstones in the Perekatnaya formation (Albian-Turonian).Materials and methods. The work was based on the materials obtained during the course of fieldwork in the Ust-Belsky Mountains (Koryak Highlands) undertaken in 2011 and 2016 by researchers from the Geological Institute of the Russian Academy of Sciences. The collected samples of sedimentary rocks were comprehensively studied using granulometric and mineralogical analysis based on the petrographic method.Results. The tuff-sandstones under study were represented by quartz-feldspar, feldspar and proper greywacke. The lithoclast composition was dominated by acidic and intermediate rock fragments. Specimens with a high lithoclast content value were characterized by a lower amount of quartz and feldspars, as well as by a larger grain size. An increase in the proportion of lithoclasts and the coarsening of grains are shown to occur from the southeast to the northwest. This fact has allowed us to establish the direction of material migration from the source area, which was located in the northwestern part of the region. According to the results of granulometric and mineralogical studies, the sediments appear to have been formed by high-speed turbidity currents under moderately deep marine conditions and at a relatively little distance from the coast, where the rivers (their deltas) provided sufficient amount of clastic material.Conclusion. The obtained data confirm the assumptions about the evolution of the Perekatnaya formation under marine conditions on a continental margin (slope). The conditions for the sedimentation of the tuff-sandstones under study can be compared with those typical of areas in the vicinity of river deltas and/or prodelts. The sedimentation occurred concurrently with volcanism, which was associated with the existence of an active continental margin (Okhotsk-Chukotka volcanoplutonic belt).
- Published
- 2019
- Full Text
- View/download PDF
50. Late Pleistocene cryogenesis features of a loess-paleosol sequence in the Srednyaya Akhtuba reference section, Lower Volga river valley, Russia.
- Author
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Taratunina, N., Rogov, V., Streletskaya, I., Thomson, W., Kurchatova, A., Yanina, T., and Kurbanov, R.
- Subjects
- *
OPTICALLY stimulated luminescence dating , *PLEISTOCENE Epoch , *ALLUVIUM , *PARTICLE size distribution , *MATERIAL plasticity - Abstract
Permafrost is considered to be one of the important sources of additional water for the vast Late Quaternary Caspian Sea transgressions. The insufficiency of proxy evidence on landscape and climate dynamics during the long Atelian regression (MIS 4 – MIS 3) complicates the analysis of changes in the Caspian water balance. Traces of Late Pleistocene cryogenesis structures were catalogued in the alluvial and loess-soil deposits of the Srednyaya Akhtuba reference section. Four stages of permafrost development were described for the first time in the Lower Volga region. Under conditions of seasonal and longer-term freezing in the Late Pleistocene, cryogenic transformation of the deposits took place; this determined the composition, structure and properties of the loess-paleosol complex at the site. Cryolithological, micromorphological analyzes and particle size distribution of mineral matter were carried out for each horizon, and traces of cryogenic processes were described in order to evaluate the regional paleoclimatic conditions that prevailed during their formation. Optically stimulated luminescence dating was used to establish a chronological framework for the main phases of the development of cryogenic modification in the Lower Volga region. The fourth stage of formation involved deep cracking of the substrate, which occurred during freezing in MIS 4, coincident with the Atelian regression of the Caspian Sea. The third stage is expressed as large wedge-shaped structures (pseudomorphs) on the border of loess and alluvial packages, with their formation known to be associated with the degradation of ice wedges. During the second and first stages of freezing, plastic deformation of deposits occurred. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
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